Osteopathy Journals and Research by Darren Chandler

 

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  1. Dorsal ramus: anatomy and clinical presentation

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    Anatomy

    Spinal cord --> dorsal root (sensory) & ventral root (motor) --> spinal nerve (mixed sensory & motor) --> ventral rami (motor > sensory) & dorsal rami (sensory > motor). Dorsal rami --> medial branch of dorsal rami & lateral branch of dorsal rami.

    Saito et al (2013) described the L2 spinal nerve and ventral rami as a 'continuous stem' . This is opposed to the dorsal rami that was described as a 'branch of the spinal nerve'. These authors did not specify if this was unique to L2.

    There are numerous anastomoses between adjacent dorsal rami, medial branches and lateral branches. Shuang et al (2015) confirmed the existence of the middle [intermediate] branch of the dorsal rami which connects the lateral branch to the communicating plexus. These authors acknowledge some might recognize the middle [intermediate] branch as a muscular sub-branch of the lateral branch, and generally, it is acceptable to divide the dorsal rami into the medial and the lateral branches. 

    The dorsal rami enters the back through a foramen bounded by the superior border of the transverse process, the anterior aspect of the superior articular facet joint and the intertransverse ligament (Zhou et al 2012).

    It runs posteriorly on the medial aspect of the intertransversarri muscles (Shuang et al 2015).

    The dorsal ramus then divides into the into medial and lateral branches at the junction of the facet joint and the proximal superior border of the transverse process (Zhou et al 2012). Bogduk and Long (1979) and Masini et al (2005) found the L1-L4 dorsal rami to divide into the medial and lateral branches within the intertransverse ligament.

    Bogduk et al (1982) found different branching patterns for not just the medial and lateral branches of the dorsal rami but also the intermediate branches. The branching patterns varied depending on the spinal levels:

    • L1 & L2 dorsal rami: commonly double branching occurs. This includes a medial branch and a short common stem for the lateral and intermediate branches.
    • L4>L3 dorsal rami: commonly triple branching occurs. This includes the medial, intermediate and lateral branches.
    • L5 dorsal rami: gives rise to the medial and intermediate branches as it runs in the groove formed by the S1 superior articular process and the sacral ala. The L5 dorsal rami lacks a lateral branch as there is no attachment of the iliocostalis lumborum to L5 as it is replaced by the iliolumbar ligament.

    Medial branch of the dorsal rami

    As the medial branch of the dorsal rami passes through a groove formed between the root of the transverse process and root of the superior articular process Bogduk et al (1982) found it was bound to the periosteum by a layer of connective tissue which coated the superior articular process and transverse process.

    The nerve then passes through a fibroosseous canal formed by the junction of the transverse process and the lateral aspect of the superior articular process. The roof of the canal is formed by the mammilloaccessory ligament. 

    *: Mammilloaccessory ligament is a part of the medial side of the intertransverse ligament. It extends from the mammillary process to the accessory process. It gives origin to the intertransversarii, multifidus, longissimus and iliocostalis muscles.

    The medial branch of the dorsal rami then penetrates the deep fascia near the median line to enter the subcutaneous tissue.

    The medial branch of the dorsal rami innervates:

    • Facet joints: innervates the two to three adjacent facet joints e.g. the L4 facet joint is innervated by the L3 and L4 medial branches. To innervate the facet joint the proximal nerve runs between the intertransversarii and the most lateral fibres of multifidus; the distal nerve runs deep to the multifidus (Bogduk et al 1982).
    • Multifidus: Shuang et al (2015) found this innervation to be highly specific. They found each medial branch ran on the deep aspect of the multifidus and was solely innervated by this one branch without any communicating branches. This finding was disputed by Wu et al (1997) who found the multifidus to be polysegmentally innervated.
    • Interspinous ligament and muscle: the nerve weaves medially between the fascicles of the multifidus to reach the interspinous space (Bogduk et al 1982).
    • Supraspinous ligament.

    Saito et al (2013) believed the intermediate branches are more widespread but have been regarded simply as muscular branches of the lateral branches. These authors described the anatomy of the dorsal rami as:

    • Medial branch: arises from the mammillary processes to enter the multifidus muscle.
    • Intermediate branch: arises from the accessory processes and enters the longissimus muscle.
    • Lateral branch: arises from the transverse processes and enters the iliocostalis.

    Lateral branch of the dorsal rami

    The lateral branch of dorsal rami lies in an osseous groove on the superior transverse process. It then sends branches to the iliocostalis and longissimus muscles.

    After passing the iliocostalis muscle, the main lateral branch descends approximately two vertebral segments before it pierces the dorsal layer of the thoracolumbar fascia into the subcutaneous region and supplies the skin.

    Distal anastomoses of the lateral branches have been noted < T11 and T12, T12 and L1, and L2 and L3.

    The lateral branch innervates the tissues lateral to the facet joint line e.g:

    • Iliocostalis and Longissimus muscles. 
    • Cutaneous innervation of the back and pelvis.

    Several authors regard the intermediate branch as a muscular branch of the lateral branch (Saito et al 2013). Those that classify the intermediate branch as a distinct branch of the dorsal rami found it to innervate the Longissimus (refer 'intermediate branch of the dorsal rami').

    Bogduk et al (1982) found:

    • L1 and L2 lateral branches: cross the iliac crest in the subcutaneous tissue in parallel with the T12 cutaneous branch. T12 and L1 innervate the dermatome just below the lateral iliac crest and posterior to the ASIS.
    • L1-3 lateral branches: emerge from the posterolateral surface of the iliocostalis lumborum, pierce the posterior layer of the thoracolumbar fascia and become cutaneous. L3 is bound down to the iliac crest by a bridge of connective tissue just lateral to the origin of iliocostalis lumborum. L2 and L3 lateral branches innervate the skin over the buttocks.
    • L4-L5 lateral branches: there are no cutaneous branches of the L4 and L5 lateral branches. L4 lateral branch remains intramuscular. The L5 lateral branch typically communicates with the S1 dorsal ramus.

    The lateral branch of the L5 dorsal ramus descends and merges into the S1 dorsal ramus (Zhou et al 2012).

    Bogduk et al (1982) described the L5 dorsal ramus as lacking a lateral branch dividing the dorsal ramus at this level into the medial and intermediate branches. This was due to the absence of an attachment of the iliocostalis to L5 which is replaced by the iliolumbar ligament.

    However both these authors also described the intermediate branch (Bogduk et al 1984) and lateral branch (Zhou et al 2012) of the L5 dorsal rami as innervating the longissimus thoracis as it attaches to the medial aspect of the dorsal segment of the iliac crest. Therefore both authors are probably describing the same nerve but under a different name.

    Intermediate brach of the dorsal rami

    The L3 and L4 dorsal rami (and sometimes L1 and L2) give off intermediate branches which supply the lumbar fibers of the longissimus thoracis (Zhou et al 2012) and mutifidus (L2 nerve, Saito et al 2013). 

    This branch passed between the longissimus and iliocostalis muscles and extended to the skin.

    Soft tissue relations to the dorsal rami

    Zhou et al (2012) found the most commonly affected area from dorsal rami pain is around the thoracolumbar region and involving the L1 and L2 dorsal rami (Zhou et al 2012). This was opposed to facet joint pain that most commonly affected the L4-5 and L5-S1 levels.

    Intertransversarii and intertransverse ligament

    The L1-L4 dorsal rami to divide into the medial and lateral branches within the intertransverse ligament (Bogduk and Long 1979 &  Masini et al 2005).

    The intertransverse ligament frequently blends with the intertransversarii muscle and has been described as looking more like a part of the thoracolumbar fascia rather than a true ligament (Hirsch et al 1963).

    The intertransversarii muscle and intertransverse ligament relation to the medial branch of the dorsal rami is:

    • The dorsal rami runs on the medial aspect of the intertransversarii muscle.
    • The medial branch of the dorsal ramus innervates the facet joint. To innervate the facet joint the proximal nerve runs between the intertransversarii and the most lateral fibres of multifidus; the distal nerve runs deep to the multifidus (Bogduk et al 1982).
    • Medial branch of the dorsal rami lies in the fibrosseous canal formed from the mamilloaccessory ligament that is associated with the intertransverse ligament and intertransversarri muscle.

    There are three distinct intertransversarii muscles (Gilchrist et al 2003):

    • Intertransversarii laterales ventrales: traverses proximally and distally between neighbouring transverse processes. Innervated by the ventral ramus.
    • Intertransversarii laterales dorsales: lies medial to the intertransversarii laterales ventrales. Inserts proximally to the accessory process and distally to the medial third of the adjacent transverse process below.
    • Intertransversarii mediales: attaches proximally to the accessory process, mamillary process, and mamillary-accessory ligament. Distally it inserts into the mamillary process of the vertebrae below. Innervated by the medial division of the dorsal rami.

    Due to their small size and medial location, the intertransversarii muscles are weak posterior sagittal rotators and lateral flexors of the lumbar spine. These muscles primary function may more proprioceptive in nature providing positioning feedback to the larger muscles of the spine that react to maintain proper spinal alignment. 

    The middle layer of the thoracolumbar fascia is the strongest layer of the thoracolumbar fascia and attaches to intertransverse ligaments. Hirsch et al (1963) described the intertransverse ligaments as being an extension of the thoracolumbar fascia rather than a ligament in its own right.

    This continuity from the middle layer of the thoracolumbar fascia to the intertransverse ligament allows tension from the transversus abdominis, internal oblique and external oblique to be transmitted via the middle layer of the thoracolumbar fascia to the transverse processes and intertransverse ligaments (Barker et al 2007). Gilchrist et al (2003) also found the iliocostalis lumborum attaches on to the middle layer of the thoracolumbar fascia.

    If the intertransversarii and intertransverse ligaments have a proprioceptive function then could this help explain how the lateral abdominal muscles influence segmental motion (Barker et al 2007)?

    Multifidus

    The multifidus relation to the medial branch of the dorsal rami includes:

    • Mammilloaccessory ligament is a point of attachment for the multifidus. This ligament forms the roof of the fibrosseous tunnel that the medial branch of the dorsal ramus runs through.
    • The medial branch of the dorsal ramus innervates the facet joint. To innervate the facet joint the proximal nerve runs between the intertransversarii and the most lateral fibres of multifidus; the distal nerve runs deep to the multifidus (Bogduk et al 1982).
    • The medial branch of the dorsal ramus weaves medially between the fascicles of the multifidus to reach the interspinous space (Bogduk et al 1982).

    The multifidus arises from the spinous process of L5 to as low as the fourth sacral foramen, PSIS and dorsal sacroiliac ligament. The longest fibers of the multifidus run from the spinous processes of L1 and L2 to the dorsal segment of the iliac crest.

    The multifidus is tightly adhered to the erector spinae aponeurosis at the lumbar (close to the midline) and sacral levels (Creze et al 2018). Johnson and Zang (2002) found the multifidus, longissimus thoracis and thoracolumbar fascia to be contributers to the supraspinous and interspinous ligaments. 

    Paralleling the mutlifidus relation with the medial branch of the dorsal rami the sacral attachment of the multifidus is also tightly adhered to the medial branches of the sacral dorsal rami. To illustrate how tight this adherence is when the multifidus was removed piecemeal many of these nerves were removed along side with it (Cox & Fortin 2014).

    Masaki et al (2019) paralled the work of Macintosh & Bogduk (1986) and found the lumbar multifidus is stretched effectively in trunk flexion. The addition of lateral flexion or ipsilateral rotation to flexion did not alter the effectiveness of the stretch. Flexion will also stretch the interspinous space.

    References

    The Anatomy of Dorsal Ramus Nerves and Its Implications in Lower Back Pain (2012) Linqiu Zhou, Carson D. Schneck, Zhenhai Shao.

    Clinical Anatomy and Measurement of the Medial Branch of the Spinal Dorsal Ramus (2015). Feng Shuang, Shu-Xun HouJia-Liang Zhu, Yan LiuYing Zhou, Chun-Li Zhang, Jia-Guang Tang.

    Muscular Control of the Lumbar Spine (2003). Russell V. Gilchrist, Michael E. Frey and Scott F. Nadler

    An electrophysiological demonstration of polysegmental innervation in the lumbar medial paraspinal muscles (1997). P B WuW S KingeryM L FrazierE S Date

    Analysis of the Posterior Ramus of the Lumbar Spinal Nerve: The Structure of the Posterior Ramus of the Spinal Nerve 2013). Toshiyuki Saito, Hanno Steinke, Takayoshi Miyaki,Shiro Nawa, Kanae Umemoto, Kunihisa Miyakawa, Norimitsu Wakao, Ken Asamoto, Takashi Nakano.

    The human lumbar dorsal rami (1982)N BogdukA S Wilson, and W Tynan

    The middle layer of lumbar fascia and attachments to lumbar transverse processes: implications for segmental control and fracture (2007). Priscilla J. Barker, Donna M. UrquhartIan H. StoryMarius Fahrer, and Christopher A. Briggs.

    Effects of the trunk position on muscle stiffness that reflects elongation of the lumbar erector spinae and multifidus muscles: an ultrasonic shear wave elastography study (2019). Mitsuhiro MasakiXiang Ji, Taishi YamauchiHiroshige TateuchiNoriaki Ichihashi

    Organization of the fascia and aponeurosis in the lumbar paraspinal compartment (2018). Creze M, Soubeyrand M, Nyangoh Timoh K, Gagey O.

    Regional differences within the human supraspinous and interspinous ligaments: a sheet plastination study (2002). Gillian M Johnson and Ming Zhang

    The anatomy of the lateral branches of the sacral dorsal rami: implications for radiofrequency ablation (2014). Cox R, Fortin  J.

    The biomechanics of the lumbar multifidus (1986). J E MacintoshN Bogduk

    The anatomy of the so-called "articular nerves" and their relationship to facet denervation in the treatment of low-back pain. N BogdukD M Long

    Anatomical description of the facet joint innervation and its implication in the treatment of recurrent back pain (2005). M Masini, W S Paiva, A S Araújo Jr

    THE ANATOMICAL BASIS FOR LOW BACK PAIN Studies on the presence of sensory nerve endings in ligamentous, capsular and intervertebral disc structures in the hurnnn lumbar spine (1963). CARL HIRSCH, Bo-ERIC INGELMARK and MALCOLME MILLER
     
    The anatomy of the so-called “articular nerves” and their relationship to facet denervation in the treatment of low-back pain (1979).Nikolai Bogduk and Don M. Long
  2. Fascia of the knee

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    Lateral knee fascia

    Iliotibial band

    The iliotibial band is merely a lateral expansion of the fascia lata and made up of three layers: superficial, middle and deep.

    Superficial and middle layer: encloses the tensor fascia lata anchoring it to the iliac crest. These layers unite at the distal end of the tensor fascia lata to form a tendon for the muscle. These two united layers receive fibers from the gluteus maximus and runs down the lateral thigh. As it courses down the lateral thigh Fairclough et al (2006) found the Iliotibial band continuous with the strong lateral intermuscular septum, which was firmly anchored to the linea aspera of the femur. Evans (1979) found fibers from the lateral intermuscular septum form the horizontal fibers of the iliotibial band.

    Distally, after coursing through the Biceps Femoris and Vastus Lateralis Godin et al (2017) found the distal attachments of the Iliotibial band to be: 

    • Proximal bundle: runs nearly transversely from the superficial Iliotibial band to the distal femur. Inserts on the proximal ridge of the distal femoral body, distal to the lateral intermuscular septum 53.6 mm proximal to the lateral epicondyle.
    • Distal bundle: runs from the superficial Iliotibial band from a proximal and lateral to distal and medial direction inserting on to the supracondylar flare. This could be the Kaplan fibers mentioned below under 'lateral femoral condyle and epicondyle'.
    • Lateral femoral condyle and epicondyle: Herbst et al (2017) found transverse fibers from the deep layer of the ITB (Kaplan fibers) connect the superficial ITB to the distal femoral metaphysis and condyle. These authors also found accessory insertions of the deep iliotibial band located proximal and anterior to the lateral femoral epicondyle. Fairclough et al (2006) described the attachment of the ITB to the region of, or directly to, the lateral epicondyle as strong fibrous ‘tendonous’ strands and then more ‘ligamentous’ strands between the lateral epicondyle of the femur and Gerdy's tubercle on the tibia. Variable and indinstinct insertions from the capsulo-osseous layer are also attached to the lateral epicondyle.
    • Capsulo-osseous layer: a distinct fascial portion of the deep Iliotibial band. Runs from just proximal to the lateral gastrocnemius tubercle to the lateral tibial tubercle*. Herbst et al (2017) found variable and indistinct attachments from this layer around the lateral femoral epicondyle. The capsulo-osseous layer is intimately related to the lateral knee capsule and the fascia surrounding the lateral gastrocnemius tendon and biceps femoris (Herbst et al 2017). Evans (1979) found additional attachments to the lateral meniscus.
    • Gerdy tubercle: the superficial Iliotibial band attaches on to a wide area from Gerdy tubercle anteriorly to the anterolateral and lateral tibia posteriorly. Deep fibers of the Iliotibial band attach slightly posterior to Gerdy tubercle (Herbst et al 2017).
    • Iliopatellar Band: attaches to the lateral aspect of the patella and patellar tendon. The distal edge of this portion forms the lateral patellotibial ligament, part of the lateral retinaculum.

    *: lateral tibial tubercle is loacted on the anterolateral aspect of the proximal tibia, between the Gerdy tubercle and the fibular head (Godin et al 2017).

    Herbst et al (2017) failed to the find the anterior lateral ligament on dissection. These authors found the capsulo-osseous layer of the ITB and the mid-third capsular ligament both occupied anatomic locations that are similar to that of the anterior lateral ligament. This ligament is documented as resisting internal rotation of the tibia.

    Fairclough et al (2006) found conversely to popular belief no bursa was found between the tendonous fibrous bands of the Iliotibial band and the femur. There was just adipose tissue. 

    Wilke et al (2016) found more distally the Iliotibial band connected strongly to the crural fascia which in itself was hardly seperable from the peroneal longus fascia.

    Deep layer: The deep layer of the iliotibial band emerges where the superficial and middle layers fuse distal to the tensor fascia lata (Putzer et al 2017). From here it runs deep attaching to the vastus lateralis and rectus femoris fascia. Coursing deeper still it follows the iliofemoral ligament to attach to the supraacetabular fossa between the tendon of the reflected head of the rectus femoris and the hip joint capsule. It resists hip extension.

    Williams (1879) gives a description of the attachment of the deep layer of the iliotibial band to the rectus femoris. He describes at a short distance below the insertion of the tensor fascia lata into the deep layer of the iliotibial band a strong process of fascia lata arises from the iliotibial band passing obliquely upwards and inwards to join the tendon of the rectus femoris at the junction of its two heads. It also spreads backwards over the outer surface enclosing the reflected head of the rectus femoris, to which it is very firmly adherent, being fixed above to the inferior gluteal line, anterior inferior iliac spine and below blending with the capsule of the joint. This band of fascia binds down the tendon of the reflected head of the rectus femoris and connects the two heads.

    Additional muscular attachments to the Iliotibial band include:

    ·           Vastus Lateralis (Becker et al 2010).

    ·           Biceps Femoris.

    ·           Tensor Fascia Lata.

    ·           Gluteus Maximus.

    Lateral patella retinaculum

    The lateral patella retinaculum is made up of:

    • Iliopatellar band of the ITB (ITB-P).
    • Lateral patellofemoral ligament (LPFL).
    • Lateral patellomeniscal ligament (LPML).

    Fibers from the vastus lateralis form part of the lateral patella retinaculum (Waligora et al (2009).

    Iliopatellar Band of ITB (ITB-P)

    The ITB attaches to the lateral aspect of the patella and patellar tendon. The distal edge of this portion forms the ITB-P.

    These fibres criss-cross in a predominantly transverse orientation. They are easily separated from the underlying joint capsule (Merican et al 2009).

    These fibers are by far the strongest and stiffest structure in the lateral retinaculum. Being more transverse in orientation and densely arranged they resist medial displacement forces that pull the patella away from the ITB. 

    These fibers move anteriorly when the knee is extending knee slackening the ITB-P and is conversely pulled tight when the knee is flexed. Therefore these fibers are most tightly stretched in knee flexion and medial patella deviation. 

    Lateral patellofemoral ligament (LPFL) and lateral patellomeniscal ligament (LPML) 

    These capsulo-ligamentous bands are thickened bands of the lateral joint capsule. They are not always present as distinct fibre bands,

    i. Lateral patellofemoral ligament (LPFL): patella (middle third) --> femur (distal and anterior to lateral epicondyle) (Shah et al 2017). The vastus intermedialis reinforces the LPFL (Waligora et al 2009).

    ii. Lateral patellomeniscal ligament (LPML): lateral border of the patella --> anterior aspect of the lateral meniscus.

    Medial knee fascia

    Fascia lata

    Wymenga et al (2006) identified three layers of the fascia in the medial knee:

    Layer I: superficial fascia

    The superficial fascia is subcutaneous. It blends with the pes anserine and tibial periosteum distally, it covers the sartorius and quadriceps proximally, the retinaculum anteriorly, and forms the deep crural fascia posteriorly.

    The superficial portion of layer I adheres to the sartorius. The deep portion of layer I adheres to the gracilis and semitendinosus tendons.

    Layer II: superficial medial collateral ligament

    The superficial medial collateral ligament extends from the femoral epicondyle to the anteromedial tibial crest 5–7 cm below the joint line. LaPrade (2009) found a majority of the distal attachments of the superficial medial collateral ligament to be to the semimembranosus and pes anserine bursa rather than the tibia.

    Posteriorly these fibres are continuous with the oblique fibres of layer III although this was disputed by LaPrade (2009) who found no clear connection.

    Anterior to the femoral attachment these fibres are continuous with the medial patellofemoral ligament.

    Tuncay et al (2007) found the semitendinosus and gastrocnemius tendons to lie between layer I and II.

    Just as the superficial portion of layer I adheres to the sartorius, the deep portion of layer I adheres to the gracilis and semitendinosus tendons. Tuncay et al (2007) found two fascial bands associated with the semitendinosus:

    • Dense 3–4-cm band around the gracilis and semitendinosus tendons approximately 8–10 cm proximal to their tendon insertion.
    • Fascial band originating from the semitendinosus and extending to the gastrocnemius fascia.

    Layer III: the true capsular layer and mid-third medial capsular ligament (deep medial collateral ligament)

    Layer III thickens and forms the deep medial collateral ligament as a thickening of the medial joint capsule.

    The deep medial collateral ligament (layer III) separates the superficial medial collateral ligament (layer II) from the medial meniscus.

    The deep medial collateral ligament extends from the medial femoral condyle to the meniscus and from the meniscus to the tibia.

    Proximally the deep medial collateral ligament attachment merges into the superficial medial collateral ligament fibres, but sometimes it has a distinct attachment 0.5 cm distally.

    The meniscotibial attachment of the deep medial collateral ligament is clearly separated from the superficial medial collateral ligament but blends with it posteriorly.

    Anterior to the superficial medial collateral ligament layer III is thin and loose blending with layer I into the retinaculum.

    Conjoint attachments of layers II and III

    The conjoined tissue of layers II and III forms the posteromedial capsule

    A condensation of fibres within the posteromedial capsule forms the posterior oblique ligament. This ligament is an important stabiliser of the medial side of the knee.

    The femoral attachment of the posteromedial capsule is located at the adductor tubercle.

    The posteromedial capsule is augmented by:

    • Semimembranosus tendon: inserts into the posteromedial tibia just below the joint line. It has various extensions into the posteromedial capsule and the posterior capsule.
    • Adductor Magnus tendon: LaPrade et al (2009) found the distal-medial aspect of the adductor magnus tendon had a thick fascial expansion, which fanned out posteromedially and attached to the medial gastrocnemius tendon, the capsular arm of the posterior oblique ligament and the posteromedial capsule.
    • Gastrocnemius: as well as a thick fascial attachment to the adductor magnus the medial gastrocnemius has a thin fascial band extending to the capsular arm of the posterior oblique ligament (LaPrade et al 2009).

    Medial retinaculum

    The medial retinaculum is made up of the:

    • Medial patello-femoral ligament (MPFL).
    • Medial quadriceps tendon–femoral ligament (MQTFL).
    • Medial patello-tibial ligament (MPTL).
    • Medial patello-meniscal ligament (MPML).

    Medial patello-femoral ligament (MPFL)

    The MPFL is an hourglass-shaped structure. Femur: adductor tubercle, medial femoral epicondyle and gastrocnemius tubercle --> patella: superomedial aspect (Aframian et al 2017). The patella attachments occur mainly through the aponeurosis of the vastus medialis and vastus intermedialis (Placella et al 2014).

    Wymenga et al (2006) found attachments of the superficial medial collateral ligament (femoral epicondyle --> anteromedial tibial crest) to the MPFL. Waligora et al (2009) found the MPFL (as well as the LPFL) fused with the fibrous layer of the joint capsule.

    These authors also found attachment of the posteromedial joint capsule to the MPFL attachment to the adductor tubercle.

    Tanaka (2016) found variations in these attachment finding all MPFL fibers can either attach to the patella or quadriceps tendon.

    Medial quadriceps tendon–femoral ligament (MQTFL) 

    Medial aspect of the distal quadriceps tendon --> femur: adductor tubercle region. 

    Medial patello-tibial ligament (MPTL)

    Patella: medial to the inferior pole* --> tibia: anteromedial tibia (Kruckeberg et al 2019).

    Medial patello-meniscal ligament (MPML)

    Patella: medial to the inferior pole* --> medial meniscus (Hinckel et al 2019).

    *: MPTL and MPML share a common insertion.

    Mechanics of the medial patella ligaments

    Tanaka et al (2019) found the MPFL accounts for only half of the total restraint to lateral patellar displacement.

    These authors found the remaining contributions to patellar stability are derived from the combination of the MPTL and MPML, which function primarily in greater degrees of knee flexion.

    In contrast Decante et al (2019) found during knee flexion, the upper bands (upper patella --> femur) stretched while the lower bands (lower patella --> femur) shortened.

    Posterior knee fascia

    Popliteal fascia

    Satoh et al (2016) found the popliteal fascia a single aponeurotic sheet acting as a three-layered retinaculum:

    • Layer one. The superficial layer of the popliteal fascia. Strongly interwoven with the epimysium of biceps femoris along its lateral aspect and with that of the semimembranosus along its medial aspect. This ensures that the flexor muscles remained in their correct positions.
    • Layer two. The intermediate layer: arose from the medial side of biceps femoris and merged medially with the superficial layer.
    • Layer three. The deep layer: stretched transversely between the biceps femoris and the semimembranosus.

    These authors found this fascia was innervated by the posterior femoral cutaneous or saphenous nerve. These nerves are closely related and distributed to densely packed collagen fibers in layer one (superficial layer) as free or encapsulated nerve endings. Therefore this fascia could be a source of pain in the upper region of the popliteal fossa.

    Anterior knee fascia

    Fascial layers of the anterior knee (Waligora et al 2009)

    Fibrous layers that cover the knee anteriorly consist of:

    • Superficial aponeurotic layer is a continuation of the fascia lata proximally and the crural fascia distally.
    • Intermediate layer: is subdivided into the deep and superficial midline layers.

    i. Superficial midline layer: laterally is a thick extension of the ITB. Medially is a thin expansion from the sartorius that connects to the fascia lata.

    ii. Deep midline layer: fibers creating the quadriceps and patellar tendons and the crossed fibers of the vastus medialis and vastus lateralis traveling to the tibial condyles of the opposite side.

    • Deep layer: fibrous layer. Medial and lateral to the patella. Comprises the patellofemoral and meniscopatellar ligaments.

    Myofascial relations of the quadricep tendon (Waligora et al 2009)

    Traditionally the quadriceps femoris insertion into the patella as a common tendon has been described as a three-layered arrangement: 

    • Superficial layer: rectus femoris.
    • Middle layer: vastus lateralis (including vastus lateralis obliquus) and vastus medialis (including vastus medialis obliquus).
    • Deep layer: vastus intermedialis.

    The strict segregation of these layers can be misleading on dissection.

    Superficial layer: rectus femoris

    The rectus femoris inserts on to the anterior portion of the patella tendon. Some fibers continue on to the ligamentum patella.

    The thickening of the deep fascia posterior to the rectus femoris contribute to the quadricep tendon.

    Middle layer: vastus lateralis and vastus medialis

    The vastus lateralis and vastus medialis unite to form a continuous aponeurosis that inserts onto the patella posterior to the rectus femoris and continues laterally and medially inserting into the sides of the patella.

    Thickening of the fascia posterior to the vastus medialis and vastus lateralis contribute to the quadricep tendon.

    Vastus lateralis (& vastus lateralis obliquus)

    From the vastus lateralis fibers cross superficial to the patella to the medial condyle of the tibia.

    Other fibers blends with the capsule of the knee and form part of the the lateral patellar retinaculum 

    The vastus lateralis obliquus is a distinct group of vastus lateralis fibers. They are separated from the main belly of the vastus lateralis. Much like the vastus medialis obliquus they can be classified as the more distal oblique fibers of the vastus lateralis.

    This vastus lateralis obliquus can originate from the lateral intermuscular septum or ITB and attach on to the superolateral part of the quadriceps tendon.

    These fibers provide a more direct lateral pull on the quadriceps tendon due to their lateral insertion on the quadriceps tendon.

    Vastus medialis (& vastus medialis obliquus)

    Most fibers of the vastus medialis end in an aponeurosis that blends with the medial side of the suprapatellar tendon or the rectus femoris tendon.

    More distal fibers form a tendinous expansion attaching to the medial side of the patella. Deep fibers from this expansion reinforce the joint capsule as part of the medial patellar retinaculum.

    Obliquely oriented fibers from the vastus medialis obliquus (with the vastus intermedialis) attach the MPFL to the patella (Placella et al 2014).

    As with the vastus lateralis tendinous fibers from the vastus medialis obliquus pass across the patella to attach to the lateral tibial condyle.

    Deep layer: vastus intermedialis

    The vastus intermedialis inserts through a broad, thin tendon into the base of the patella.

    Medially and laterally it reinforces the MPFL and LPFL.

    Thickening of the deep fascia anterior to the vastus intermedialis contributes to the quadricep tendon.

    References

    Lateral Patellofemoral Ligament: An Anatomic Study (2017). Kalpit N. ShahSteven F. DeFroda,  James Kristopher Ware,  Sarath C. Koruprolu, and Brett D. Owens.

    Three-layered architecture of the popliteal fascia that acts as a kinetic retinaculum for the hamstring muscles (2016). Masahiro SatohHiroyuki YoshinoAkira FujimuraJiro HitomiSumio Isogai

    The structural properties of the lateral retinaculum and capsular complex of the knee (2009). Azhar M. Merican, Sanjay Sanghavi, Farhad Iranpour, and Andrew A. Amis

    Descriptive and dynamic study of the medial patellofemoral ligament (MPFL) (2019). Cyrille DecanteLoïc GeffroyCéline SalaudAntoine ChalopinStéphane PloteauAntoine Hamel

    Variability in the Patellar Attachment of the Medial Patellofemoral Ligament (2016). Miho J Tanaka 

    The postural function of the iliotibial tract (1979). P. Evans

    The functional anatomy of the iliotibial band during flexion and extension of the knee: implications for understanding iliotibial band syndrome (2006). John Fairclough, Koji Hayashi, Hechmi Toumi, Kathleen Lyons, Graeme Bydder, Nicola Phillips,Thomas M Best, and Mike Benjamin.

    Recognition of evolving medial patellofemoral anatomy provides insight for reconstruction (2019). Miho J Tanaka, Jorge Chahla, Jack Farr, Robert F LaPrade, Elizabeth A Arendt, Vicente Sanchis-Alfonso, William R Post, John P Fulkerson

    Quantitative and Qualitative Analysis of the Medial Patellar Ligaments: An Anatomic and Radiographic Study (2018). Bradley M Kruckeberg, Jorge Chahla, Gilbert Moatshe, Mark E Cinque, Kyle J Muckenhirn, Jonathan A Godin, Taylor J Ridley, Alex W Brady, Elizabeth A Arendt , Robert F LaPrade

    Concepts of the Distal Medial Patellar Restraints: Medial Patellotibial Ligament and Medial Patellomeniscal Ligament (2019). Betina B Hinckel, Lukasz Lipinski, Elizabeth A Arendt

    Origin and insertion of the medial patellofemoral ligament: a systematic review of anatomy (2016). Arash AframianToby O. Smith, T. Duncan Tennent, Justin Peter Cobb, and Caroline Blanca Hing.

    The fascial band from semitendinosus to gastrocnemius: the critical point of hamstring harvesting An anatomical study of 23 cadavers (2007) Ibrahim Tuncay, Hudaverdi Kucuker, Ibrahim Uzun and Nazim Karalezl

    The Anatomy of the Medial Part of the Knee (2009). Robert F. LaPrade, Anders Hauge Engebretsen, Thuan V. Ly, Steinar Johansen, Fred A. Wentorf, Lars Engebretsen

    Surgical anatomy of the medial collateral ligament and the posteromedial capsule of the knee (2006) Ate B Wymenga Sint Maartenskliniek, Jan-Jaap Kats, Jan G M Kooloos

    A Comprehensive Reanalysis of the Distal Iliotibial Band Quantitative Anatomy, Radiographic Markers, and Biomechanical Properties (2017). Jonathan A. Godin Jorge Chahla, Gilbert Moatshe, Bradley M. Kruckeberg, Kyle J. Muckenhirn, Alexander R. Vap, Andrew G. Geeslin, Robert F. LaPrade

    The Anterolateral Complex of the Knee (2017). Elmar Herbst, Marcio Albers, Jeremy M. Burnham, Freddie H. Fu, and Volker Musahl.

    Anatomical study of the morphological continuity between iliotibial tract and the fibularis longus fascia (2016). Wilke J, Engeroff T, Nürnberger F, Vogt L, Banzer W.

    Clinical Anatomy of the Quadriceps Femoris and Extensor Apparatus of the Knee (2009). Andrew C. WaligoraNorman A. Johanson, and Bruce Elliot Hirsch.

    Shape and size of the medial patellofemoral ligament for the best surgical reconstruction: a human cadaveric study (2016). G PlacellaM M TeiE SebastianiG CriscentiA SpezialiC MazzolaA GeorgoulisG Cerulli